Method for monitoring drive components in a large hydraulic excavator

ABSTRACT

A method for continuously and simultaneously monitoring a plurality of operatively connected mechanical and/or hydraulic drive components provided in at least one drive train in a large hydraulic excavator by virtue of a vibration sensor being positioned in the region of just a single one of the operatively connected drive components, the vibration sensor being connected by a line to an evaluation unit which contains prescribable conspicuousness patterns for all the operatively connected drive components, and the collective measurement signal from all the operatively connected drive components being aligned in conditioned form, as an input frequency, with a limit value—associated with the respective individual drive component—from the conspicuousness pattern.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to international patent application number PCT/EP2011/003815, having a filing date of Jul. 29, 2011, which claims the benefit of priority to German patent application number DE102010033344.1, having a filing date of Aug. 4, 2010, the complete disclosures of which are hereby incorporated by reference for all purposes.

TECHNICAL FIELD

The invention relates to a method for continuously and simultaneously monitoring a number of drive components provided in at least one drive train of a large hydraulic excavator.

BACKGROUND

Large hydraulic excavators with a service weight in excess of 100 t are generally used in mining operations, where they are often in continuous use over a long time during the day. At predetermined time intervals, these large hydraulic excavators undergo servicing work, including the exchange of certain components, such as for example clutches or the like, at certain intervals.

Nevertheless, in the tough day-to-day operation of large hydraulic excavators there are continually recurring instances of operationally relevant components, such as for example gearboxes, pumps or the like, becoming damaged between service intervals, possibly attributable to material defects and/or system faults.

DE 101 00 522 discloses a monitoring device for monitoring the function of a machine, in particular an agricultural machine, with at least one sensor, which is designed for providing a signal which contains information about a noise that is caused by at least one movable element of the machine. Proposed is a computer device which receives the signal of the sensor and can be operated on the basis of the signal provided by the sensor and a comparative value to generate a signal value. In this way, error messages can be generated.

DE 10 2005 059 564 A1 discloses a device for monitoring the state of hydrostatic displacement units, in particular in the case of axial piston machines operated as a pump or as a motor. The device comprises a recording unit with a multiplicity of sensors attached to the hydrostatic displacement unit for recording monitoring and operating data and also an evaluating unit, which has a device for analyzing the monitoring data in the frequency range of a device for analyzing the monitoring data in the time range. The evaluating unit is adjoined by a diagnostic unit with an output unit.

DE 10 2005 023 256 A1 describes a monitoring device for monitoring the function of the components of an agricultural machine, with a vibration sensor for providing signal values which contain information about mechanical vibrations caused by movable components of the machine, an operating state recording device for providing a signal which contains information about the operating state of components of the machine and a computer device for generating state information regarding the state of the components of the machine that is based on the signal values of the operating state recording device and the vibration sensor.

SUMMARY

The aim of the subject matter of the invention is to detect changes in the operating behavior of drive components in the area of a large hydraulic excavator with a service weight in excess of 100 t in good time and thereby give the operator of the respective machine the possibility of being able to implement maintenance or repair measures or the exchange of damaged drive components without delay, in order to avoid additional unplanned inoperative times outside the service intervals. The method is intended to be applicable both to diesel drives and electromotive drives in single- or multi-engine or motor operation.

It is also intended to provide a device for monitoring drive components provided in the area of a large hydraulic excavator with a service weight in excess of 100 t that minimizes unplanned inoperative times of the large hydraulic excavator.

This aim is achieved by a method for continuously and simultaneously monitoring a number of mechanical and/or hydraulic drive components provided in at least one drive train of a large hydraulic excavator and in operative connection with one another, in that a vibration pickup is positioned in the area of just a single one of the drive components in operative connection with one another, this vibration pickup is connected via a line to an evaluation unit, which contains predeterminable peculiarity patterns of all the drive components in operative connection with one another and transmits the common measuring signal of all the drive components in operative connection with one another in a prepared form as an input frequency to the evaluation unit and adjusts there a limit value from the peculiarity pattern that belongs to the respective individual drive component.

Advantageous developments of the method according to the invention can be taken from the associated method-related dependent claims.

The subject matter of the invention discloses a method for continuously and simultaneously monitoring drive components of at least one drive train of a large hydraulic excavator provided with a diesel or electric drive, so that the respective operator of the large hydraulic excavator can arrange maintenance or repair measures or the exchange of the damaged component in good time—even outside normal service intervals.

Consequently, unplanned inoperative times of the large hydraulic excavator are avoided. Drive components in the sense of the subject matter of the invention are, for example, pump power dividers, swiveling gear mechanisms, hydraulic pumps, hydraulic motors and also the respective diesel engine or electric motor.

As a departure from the prior art, a dedicated sensor is not used for each individual component, but rather the aggregate oscillation of the drive components in operative connection with one another of at least one drive train of the large hydraulic excavator is determined. It is often the case with large hydraulic excavators that the following components are mechanically and/or hydraulically brought into operative connection with one another: the drive motor, the clutch, the pump power divider and hydraulic pumps.

This aim is also achieved by a device for continuously and simultaneously monitoring a number of drive components in operative connection with one another in at least one drive train of a large hydraulic excavator with a service weight in excess of 100 t, comprising a vibration pickup which is fixedly connected to the housing of a single one of the drive components in operative connection with one another and is in operative connection via a line with an evaluation unit provided in the area of the large hydraulic excavator.

The subject matter of the invention involves the following advantages:

-   -   simpler sensor systems in comparison with a vibration pickup on         rotational parts,     -   linking of the measurement data with further machine-relevant         data,     -   introduction of the component data into the on-board electronic         system,     -   component diagnostics.

According to a further idea of the invention, the frequency pattern predetermined for the drive component respectively to be monitored and stored in the evaluation unit is stored in the evaluation unit as a limit value that is dependent on the respective rotational speed of the engine or motor.

The evaluation unit may be part of the large hydraulic excavator. The measurement data may, if need be, also be correlated with other machine-relevant data, for example with data from the vehicle's electronic system. Linking all of the data allows conclusions to be drawn as to why the limiting frequency range of the respective drive component was exceeded.

If the evaluation unit is part of the large hydraulic excavator, the state of the drive components can be displayed by suitable display elements, on a monitor for example, and thus be monitored, if appropriate with further data, by the driver of the large hydraulic excavator.

An electronic evaluation system may also be arranged decentrally (for example with radio transmission), so that the suitable repair measures can be initiated from there.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter according to the invention is represented in the drawing on the basis of an exemplary embodiment and is described as follows. In the drawing:

FIG. 1 shows a basic diagram of an only indicated large hydraulic excavator;

FIG. 2 shows a schematic representation of a drive train of the large hydraulic excavator according to FIG. 1.

DETAILED DESCRIPTION

FIG. 1 shows as a basic diagram an only indicated large hydraulic excavator 1 with a service weight in excess of 100 t, as can be used for example for extracting oil shale in a mine. Only the relevant components are represented, such as the superstructure 2 swivel-mounted on a crawler undercarriage 3, and the driver's cab 4. Likewise only indicated is one of the drive trains 5 (6), in this example comprising a diesel engine 7, a clutch 8, a pump power divider 9 and hydraulic pumps 10, 11 mechanically flange-mounted on the pump power divider. Also indicated is an evaluation unit 15, provided in the area of the driver's cab 4 and comprising an optical display.

Further drive components, such as hydraulic motors, swiveling gear mechanisms or the like, are only indicated, but are also covered by the scope of protection.

FIG. 2 schematically shows one of the drive areas of the large hydraulic excavator 1 according to FIG. 1. Indicated in this example is a drive train 5, comprising a diesel engine 7, a clutch 8, a pump power divider 9 and hydraulic pumps 10, 11. These drive components 7, 8, 9, 10, 11 are mechanically/hydraulically in operative connection with one another, and consequently can be regarded as a unit. In this example, it is intended that exclusively on the pump power divider 9 there is fixedly mounted a single vibration pickup 12. The measuring signals of the vibration pickup 12 are fed via a line 13 to the evaluation unit 15 provided in the driver's cab 4 of the large hydraulic excavator 1.

In the evaluation unit 15, a specific peculiarity pattern 14 is stored for each of the drive components 7, 8, 9, 10, 11 in operative connection with one another of the drive train 5, so that the possible defective component can be detected by way of these defined patterns and their amplitudes. These patterns are coupled to an only indicated electronic evaluation system 16, which in turn is in connection with the BCS (Board Control System) of the large hydraulic excavator 1 and, if need be, displays to the operator information about an operating state deviating from the normal case of one or more of the drive components 7, 8, 9, 10, 11 by way of optical display 17.

Alternatively or in parallel, the transmission of the measurement data may also be relayed by radio to an external monitoring center, so that then the adjustment between the measured value and the limit value can be performed there. If need be, necessary repair measures can then be initiated here.

The vibration pickup 12 continuously and simultaneously records an aggregate measuring signal, preferably the vibration frequencies of the respective drive component 7, 8, 9, 10, 11. This aggregate signal is fed to the display 17 via the line 13′. In the evaluation unit 15, a constant adjustment takes place between the input frequency and the different peculiarity patterns (limit values) stored there of the respective drive components 7, 8, 9, 10, 11. Deviations between the actual frequency of the respective drive component 7, 8, 9, 10, 11 and the stored critical limit values 18, 18′, 18″ are generated in dependence on the respective rotational speed of the engine 7 in a peculiarity message and are stored in the fault memory of an on-board control system. Consequently, a dedicated limit value 18, 18′, 18″ is defined in association with each engine speed for each of the drive components 7, 8, 9, 10, 11 in operative connection with one another. As a departure from the prior art, consequently, there are always varying limit values 18, 18′, 18″ for the individual drive components 7, 8, 9, 10, 11, which bring about a high degree of flexibility in the data preparation. The peculiarity message is fed with further relevant machine data (such as for example engine speed, temperature, pressure of the pumps 10, 11) via further sensors 19, 20 and associated lines 21, 22, 23, 24 to the display 17 of the on-board control system.

For each signal of the respective drive component 7, 8, 9, 10, 11 that is stored in the evaluation unit 15, a specific peculiarity pattern is generated, so that, by way of these defined peculiarities and the comparison with the signals supplied by the vibration pickup 12, the possible defective drive component can be detected. 

1. A method for continuously and simultaneously monitoring a number of mechanical and/or hydraulic drive components provided in at least one drive train of a large hydraulic excavator and in operative connection with one another, comprising: a vibration pickup is positioned in the area of just a single one of the drive components in operative connection with one another; wherein the vibration pickup is connected via a line to an evaluation unit, which contains predeterminable peculiarity patterns of all the drive components in operative connection with one another and transmits a common measuring signal of all the drive components in operative connection with one another in a prepared form as an input frequency with a limit value from the peculiarity pattern that belongs to the respective individual drive component.
 2. The method as claimed in claim 1, wherein the peculiarity pattern for the respective drive component is stored within the evaluation unit as a limit value that is dependent on the rotational speed of the engine or motor.
 3. The method as claimed in claim 1, wherein the vibration pickup is secured to the housing of the drive component.
 4. The method as claimed in claim 1, wherein the evaluation unit is coupled to an electronic evaluation system, in which further machine-relevant operating parameters are stored.
 5. The method as claimed in claim 4, wherein the evaluation unit is formed as a component part of the electronic monitoring of the large hydraulic excavator.
 6. The method as claimed in claim 5, wherein the data prepared by the evaluation unit located in the large hydraulic excavator are made available wirelessly to an external location.
 7. The method as claimed in claim 1, wherein both the respective limit value of the drive components in operative connection with one another and their exceeding of a limit value are displayed at least on an optical display provided in the driver's cab of the large hydraulic excavator.
 8. The method as claimed in claim 7, wherein, when the data exceed a limit value, an optical and/or acoustic signal is triggered.
 9. A device for continuously and simultaneously monitoring a number of drive components in operative connection with one another in at least one drive train of a large hydraulic excavator with a service weight in excess of 100 t, comprising: a vibration pickup which is fixedly connected to the housing of a single one of the drive components in operative connection with one another and is connected via a line to an evaluation unit provided in the area of the large hydraulic excavator.
 10. The device as claimed in claim 9, wherein the evaluation unit is in operative connection with an electronic evaluation system, within which further machine-relevant data can be stored and can be correlated with the data from the evaluation unit. 